By analyzing the summer satellite data from 2000 to 2007,it shows that some of mesoscale cloud clusters resulting in regional or largescale rainstorm in Shandong province experience the process from nonorganized system to organized system,from irregular cloud pattern to regular cloud pattern.To study the features of the evolution,six typical events are studied.The results show that the cloud clusters selforganization causing the heavy rainstorm in Shandong province occurs in July,there are 5 pieces of cloud clusters on average at the beginning,the average distance between the cloud clusters is 200 km,most cloud clusters build in the west of Shandong province and in the boundary of Shandong,Henan and Hebei provinces,the 1hr strongest precipitation generally happens within three hours before or after the completion of selforganization,and the cloud clusters lasts for about 11 hours from building over selforganization to extinction.